How GIS Has Changed Our World

This map on michiganradio.org from February 1st, depicts the results of home lead tests in Flint. The test information, gathered by the State, was then grouped into the following categories to make this map:

0 ppb – no lead detected in the drinking water

1-4 ppb – the EPA deems this range as acceptable

5-14 ppb – exposure is a concern, but still below an EPA “federal action level”

15-49 ppb – a range above the federal action level for lead, but can be treated by filters

50-149 ppb – reaching dangerous levels, but can be treated by filters

150 and above – a range at which the federal government says water filters might not work

Looking at this map, trying to determine the source is difficult because no real pattern can be determined. Makes you think about what other areas in the US have horrible water that either hasn’t been discovered yet, or just taken seriously.